Description / Abstract:
This recommended practice provides a procedure for measuring and
documenting the aerodynamic performance in a fullscale wind tunnel
of passenger vehicles, i.e., mass-produced cars and light-duty
trucks intended primarily for individual consumers. Testing or
numerical modeling of pre-production and/or reduced-scale models is
outside the scope of this document. Aerodynamic development
procedures, i.e., methods to improve or optimize aerodynamic
performance, are also excluded.
It is well-known that aerodynamic performance results depend
significantly on vehicle content and loading, as well as the wind
tunnel itself (type, scale, and simulation qualities of the wind
tunnel). Publication of non-standard test results causes
unnecessary additional development work and incorrect perception of
a vehicle's anticipated aerodynamic performance by government,
academia, and the general public.
The intent of this document is to promote uniformity and
traceability of published aerodynamic performance data acquired in
a wind tunnel, thereby enhancing the public reputation and
credibility of the aerodynamics discipline in the total vehicle
development process.
Measurement of the aerodynamic performance according to this
recommended practice requires a full-scale wind tunnel test on a
production-ready, full-scale vehicle according to specifications
for vehicle loading, content, and wind tunnel conditions.
The measurement and resulting documentation for a particular
vehicle shall be reported only by the company that intends to
produce the vehicle. Whenever there is an opportunity for
interpretation of the document, a good faith effort shall be made
to obtain the vehicle's typical in-service performance and avoid
finding the best possible performance under the best possible
circumstances.
Use of and compliance with this recommended practice is
voluntary; however, it is mandatory for those advertising or
otherwise publishing aerodynamic performance as "measured according
to SAE J2881". Conversely, any advertised or otherwise published
result carrying this or a substantially similar designation must
have the necessary documentation accepted by and on file with the
SAE in accordance with the procedures defined in this recommended
practice.
Appendices B and C contain the necessary submittal documents for
compliance with this recommended practice. When a submittal is
made, the chairman of the Road Vehicle Aerodynamics Committee (or
his/her designee) shall review the submittal for proper completion
according to the requirements herein, but without consideration of
the technical merit of the claimed performance. After the
chairman's review, SAE will maintain an electronic database of all
submittals.
The database shall be available only to members of the Road
Vehicle Aerodynamics Committee. Any RVAC member who retrieves
information from the database shall do so with the understanding
that the information is to be considered confidential within his or
her company.